...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Physical review >Vibrational Modes In Zngen_2: Raman Study And Theory
【24h】

Vibrational Modes In Zngen_2: Raman Study And Theory

机译：Zngen_2的振动模式：拉曼研究和理论

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Polarized Raman spectra were measured for single crystals and polycrystalline ZnGeN_2 grown by a vapor-liquid-solid method. A group-theoretical analysis of the selection rules governing the predicted dependence of the spectra on incoming and outgoing wave polarizations and propagation direction is presented. First-order Raman spectra corresponding to the zone center phonons are calculated from first principles using density functional perturbation theory. The Brillouin zone integrated density of phonon states is also calculated. Comparison of theory and experiment allows us to identify the a_(1t) symmetry modes. However, vibrational density of states features deviating from the pure a_(1t) spectrum are also visible in the experimental spectra and indicate some relaxation of momentum conservation rules. Differences in the experimental spectra under different polarization conditions are compared to the calculations. These differences allow us to identify different a_(1t) Raman tensor components as well as to obtain at least partial information on the b_(2t) modes. The much weaker polarization dependence in experiment than in theory, however, can at least in part be explained by using wurtzite-type selection rules. The observation of features explainable with wurtzite together with orthorhombic selection rules suggest that there is only partial ordering of the cations on their sublattice.
机译：测量了通过汽-液-固方法生长的单晶和多晶ZnGeN_2的极化拉曼光谱。提出了选择规则的群论分析，这些规则控制着光谱对入射波偏振和出射波偏振以及传播方向的预测依赖性。使用密度泛函微扰理论从第一原理计算出与区域中心声子相对应的一阶拉曼光谱。还计算了布里渊区声子态的积分密度。理论和实验的比较使我们能够确定a_（1t）对称模式。然而，偏离纯a_（1t）光谱的状态特征的振动密度在实验光谱中也可见，表明动量守恒规则有所放松。将不同偏振条件下的实验光谱差异与计算结果进行比较。这些差异使我们能够识别不同的a_（1t）拉曼张量分量，并获得关于b_（2t）模式的至少部分信息。然而，实验中比理论上弱得多的偏振依赖性可以至少部分地通过使用纤锌矿型选择规则来解释。通过纤锌矿和斜方晶选择规则可以解释的特征的观察表明，阳离子在其亚晶格上只有部分顺序。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号